Apparatus for electrically forming spiral piston rings



March 1 1927. 1,619,296

H. 5. GRAVES AEPARATUSFOR ELECTRICALLY FORMING SPIRAL PISTON RINGS Filed Ausz. 15, 1925 3 Sheets-Sheet l H. S. GRAVES APPARATUS FOR ELECTRICALLY FORMING SPIRAL PISTON RINGS March 1 1927. 1,619,296

gwownkoz fir? 5f Graves,

H. s. GRAVES Arrmnusfoa ELECTRICALLY FORMING srnm. PISTON runes Filed Auz. 15, 1925 3 Sheets-Sheet 5 gwvmto fifzrzy c5 670065,

latented l, 1927.

UNITED STATES HAIRY (IR-AVIS, OI DETROIT, MICHIGAN, ASBIGNOB .lO SPIRAL PISTON m6 PATENT OFFICE.

comm, DETROIT, IIOHIGAN, A COBPORLTIOII OI IIOHIGAI.

mm'rus roa ILECTBICALLY romtme srnuu. rrs-rou mes.

Application ma August 15, 1925. Serial Io. miss.

This invention relates to piston ring form in machines and my invention aims to provi 0 a machine in which split circular rings may be expeditiously and economicallgeconverted into spiral rings which may advantageously used in connection with various types of pistons, particularly formternal combustion engines.

My invention furt er aims to provide a machine for grippin split pistonrin subjectin the rings to eat, and then 0 setting one end of the ring for a spiral formation, the ri being released to drop into a tempering iath which sets the spiral formatlon of the ring.

My invention still further aims to provide a process of offsetting split rings to imart a spiral formation thereto, the process including progressively performed operations, to w1t :first, holding the split ring so that one end thereof may be shifted at an angle to the plane of the ring; second, electrically heating said ring by passing an electric current throu h the ring and its holding means; third, s 'ftin an end of the rin during the application 0 heat, to offset suc end relative to the other end of the ring, and then releasing the ring so that it may be tem red.

y invention includes an organization of instrumentalities by which rings may be safely heated by electricity and the construction entering into the machine will be hereinafter specifically described and then claimed.

Reference will now be had to the drawwhereinigure 1 is a front elevation of the machine partly in section;

Fig. 2 is a plan of the machine partly 1n section;

Fig. 3 is a vertical cross sectional view of the machine;

Fig. 4 is a view of one end of the machine;

Fig. 5 is a view of the opposite end of the machine;

Figs. 6 to 8 inclusive are diagrammatic views of ring gripping jaws showing the forming of a spiral ring from an ordlnary split ring;

Fig. 9 is a perspective view of a split or embryo ring, and

Fig. 10 is a similar view of the same rmg after having a spiral formation imparted thereto In the drawings, the reference numeral 1 denotes a work bench or table and suitably secured thereto by bolt equipped nuts 2 or other fastening means is an overhan' g support 3 having its front edge as at 4, to provide clearance .for a set of ring gripping jaws that will be hereinafter described.

Mounted on the ends of the support 3 are brackets 5 and 6 and attached to said brackets by screws 7 or other fastening means is a double T-head 8 having its front and rear sides provided with slide-ways 9 and one end cut away, as at 10.

In the rear guideway' of the head 8 are jaw blocks 11 and 12 and in the front guideway are jaw blocks 13 and 14. The jaw blocks 11 and 12 have a set of depending jaws 15 adapted to cooperate with another set of jaws 16 carried by the blocks 13 and 14 for gripping the split end portions 17 of a ring 18, best shown in Fig. 9. The jaw blocks 11 to 14 inclusive have a dove-tail con nection with the head 8 and all of the jaw blocks are slidable in said 'head, with the exception of the jaw block 14 WhlOh is fixed to the head by a screw bolt 19 or other fastening means. The jaws 15 and,16 are insulated from the blocks 11 and 14 inclusive by insulation washers 20 and insulation sleeves 21, said washers and sleeves accommodating nut equipped bolts 22 by which the jaws are connected to the blocks and said nut equipped bolts serve as binding posts, as will hereinafter appear.

Interposed between the confronting ends of the blocks 11 and 12 and the confronting ends of the blocks 13 and 14 are coiled light duty springs 23 adapted to have the expansive force thereof hold the jaw blocks 11 and 13 open relative to the jaw blocks 12 and 14 so that the split end portions 17 of the ring 18 may be easily placed between the jaws of each set to be gripped and temporarily held thereby.

Slidable in the guideways of the head 8 are cross heads 24 and interposed between said cross heads and the blocks 11 and 13 are heavy duty coiled expansion springs 25. The cross heads 24 are provided with ad'- justable abutments 26, preferably in the form of screw bolts, adapted to be engaged by cam engagin members 27 slidable 1n the guideways of t e head 8. These cam engaging members are normally engagedby a cam 29 mounted on the end of a shaft 30, journaled in the bracket 5. The oppo end of the shaft has a cam 31 and a sprocket wheel. 32.

Journaled in the bracket 6 is a shaft 33 provided with a sprocket wheel 34 and a cam 35, said cam bein adapted to engage the jaw block 12 and s ift this block along with the block 11 so that the set of aws 15 ma be shifted relative to the set of aws 16.

rained about the sprocket wheels 32 and 34 is an endless sprocket chain 36 adapted to be driven by a sprocket wheel 37 on a shaft 38, journaled in a gear housing 39 suitably secured to the support 3. In the gear housing 39 and on the shaft 38 is a worm wheel 40 meshing with a worm 41 adapted to be driven from an electric motor 42 mounted on the support 3. The motor 42 may be driven from a suitable source of energy and its operation controlled by a conventional form of switch. The sprocket wheels and chain are a fair example of a power transmission mechanism by which the shafts 30 and 33 may be driven in synchronism, and while the cams are adapted for shifting the slidable blocks, cross heads and cam en aging members in certain directions, the springs 23 and 25 are adapted for shifting the slidable blocks, cross heads and cam en aging members in other directions.

11 the support 3, preferably at the rear side thereof, is an insulator 43 provided with connectors 44 for leading in wires 45 from a suitable source of electrical energy. One of the connectors 44 is connected by wires 46 to the set of jaws 15 and the other-connector is connected by a wire 47 to a contact member 48 mounted at a switch housing 49 suitably supported from a head 8. In the switchhousing 49 is pivotally mounted a spring pressed lever 50 which extends throug an openin 51 in the bottom of the switch housing and has an angular end 52 in the path of the cam 31 so as to be actuated thereby. The upper or opposite end of the pivoted lever 50 has a contact member 53 adapted to engage the contact member 48 and complete an electric circuit. The contact member 53 is connected by a wire 54 to a binding post 55 of the switch housing and said binding post is connected by wires 56 and 57 to the set of jaws 16. The contact members 48 and 53 and the binding post 55 are suitably insulated from their supports.

When the motor 42 is placed in operation the shafts 30 and 33 are driven in synchronism and the jaw blocks 11, 12 and 13 are shifted so that the jaws are caused to grip the split end portions 17 of the ring 18 and then hold one end of the ring while the opposite end of the ring is shifted to offset it relative to the plane of the ring,'thereby imparting a spiral formation to the ring, as shown in Fig. 10. The jaw block 14 being site.

stationary and the jaw block 12 abutting the cam 35 permits the expansive forces of the springs 23 and 25 to at all times retain the cam engaging members 27 in engagement with the cam 29. When the cam 29 becomes active the members 27 and the blocks 24 are shifted towards the 'aw blocks 11 and 13 and by virtue of the eavy duty springs 25 the 'aw blocks 11 and 13 are moved towards the jaw blocks 12 and 14 which are now stationary. The light duty springs 23 are compressed and the split end portions 17 of the ring 18 are clamped between the jaws 15 and 16 with the p we of the ring at a right angl e to the direction of travel of said jaws. ith the ring "ripped b the jaws the cam 31 actuates t e pivote lever 50 and closes an electric circuit at the contact members 48 and 53 whereby there is current flowing through the jaws 15 about .the ring 18 to thejaws 16, thus causing the ring 18 to be heated to such an extent that it may be reshaped or easily distorted. The electrical connections are clearly shown in Figs. 6 to 8 inclusive and by observin these .views it will be noted that a circuit may be provided by simply making connections with one jaw of each set, but by having electrical connections about all of the jaws a better electrical contact is established with the sides of the ring for heating urposes.

When the ring is in a heated condition the cam 35 actuates the jaw block 12 and through the medium of the spring 23 between the blocks 11 and 12, said blocks are shifted in synchronism carrying the set of jaws 15 out of transverse alinement with the set of jaws 16, thereby offsetting one end portion of the split ring relative to the other end portion, thus im arting the spiral formation to the ring. ext, the cams 29, 31 and 35 permit the current to be shut off and the jaws opened to release the offset rin so that it may drop into a tempering bat 58 in a receptacle 59 placed below the jaws 15 and 16. The expansive forces of the springs 23 and 25 cause the jaws to assume normal position so that another ring may be immediately placed in position by an attendant of the machine to have a spiral formation imparted thereto.

If no ring is in position to be gripped by the jaws there is no contact of the jaws and consequently no electrical circuit completed, because it requires a ring in position and gripped by the jaws to complete an electric heating circuit. The operation of the machine is timed so that each ring will be thoroughly heated before being offset and. the only manual operation, after starting the machine, is that of placing rings in position to be gripped by the jaws.

From the foregoin operation of the machine it will be note that a process is involved that may be carried into effect by a machine that may be structurally difierentfrom the machine herein shown, but the rocess necessarily includes some means of olding'the ring in order to subject it to heat and then ofiset one end of the ring relative to the other end so as to impart a spiral formation to the ring. I prefer to accom lish the heating through the same means w ich holds the prising clamping means for the ends of-the split ring, means for electrically heating said ring by the application of current to said clamping means, and means adapted for shifting a portion of said clamping means to impart a-spiral formation to] said ring.

2. A machine of the'type described including sets of jaws adapted to grip the ends of a split ring, means adapted to shift someof sald jaws for ring gripping purposes, means set in action by the jaw shifting means for applying heat to said ring to render it malleable, and means adapted to shift one set of jaws relative to the other set of jaws, during the application of heat, to impart a spira formation to said rm A machine as called for in claim 2, wherein the jaw shifting means includes motor driven cams.

means at 4. A machine as called for in claim 2, wherein. the second mentioned means includes an electric circuit with said jaws. in said electric circuit.

5. A machine as called for in claim 2,

wherein the second mentioned means 'includes an electric circuit and a cam actuated switch controlling said circuit.

6. A machine of the type described comprising a head, a set of jaws at each side of ;aid head and extending under said head or r1n ri pin pur oses jaw actuatin g tfiie ends of said head to cause said jaws to rip a ring, electrical connection for said aws, and means adapted to move one set of jaws while the other set of jaws are held stationary.

7. A machine of the type described comprising a head, a set of jaws at each side of staid head and extending under said head or ring ippi pur ses, 'aw actuating means at Si e end s of said head to cause said jaws to grip a ring-electrical connections for said jaws, a switch controlling the cur rent to said jaws independent of the other set of jaws for offsetting an end of the ring, and switch operating means operatable in the interim of gripping the ring and offsetting the ring.

8. machine as called for in claim 7, wherein jaw actuating means and said switch operating means are coaxial and driven from acommon sourceof power.

It testimony whereof I aflix my signature.

HARRY S. GRAVES. 

